1602.c

1602液晶测试程序, RS EQU P3.7 RW EQU P3.6 E EQU P3.5

//使用1602液晶显示的实验例子
//(转载)SMC1602A(16*2)模拟口线接线方式(原著:明皓)
//连接线图: 
//       ---------------------------------------------------
//       |LCM-----51   | LCM-----51   | LCM------51      |
//       --------------------------------------------------|
//       |DB0-----P1.0 | DB4-----P1.4 | RW-------P2.0    |
//       |DB1-----P1.1 | DB5-----P1.5 | RS-------P2.1    |
//       |DB2-----P1.2 | DB6-----P1.6 | E--------P2.2    |
//       |DB3-----P1.3 | DB7-----P1.7 | VLCD接1K电阻到GND|
//       ---------------------------------------------------
// 
//[注:AT89S51使用12M晶振]
//=============================================================
#define LCM_RW  P2_0 //定义引脚
#define LCM_RS  P2_1
#define LCM_E   P2_2
#define LCM_Data  P1
#define Busy    0x80 //用于检测LCM状态字中的Busy标识
#include  <at89x51.h>
void WriteDataLCM(unsigned char WDLCM);
void WriteCommandLCM(unsigned char WCLCM,BuysC);
unsigned char ReadDataLCM(void);
unsigned char ReadStatusLCM(void);
void LCMInit(void);
void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData);
void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData);
void Delay5Ms(void);
void Delay400Ms(void);
unsigned char code uctech[] = {"uctech"};
unsigned char code net[] = {"uctech.icpcn.com"};
void main(void)
{
 Delay400Ms(); //启动等待，等LCM讲入工作状态
 LCMInit(); //LCM初始化
 Delay5Ms(); //延时片刻(可不要)
 DisplayListChar(0, 5, uctech);
 DisplayListChar(0, 0, net);
 ReadDataLCM();//测试用句无意义
 while(1);
}
//写数据
void WriteDataLCM(unsigned char WDLCM)
{
 ReadStatusLCM(); //检测忙
 LCM_Data = WDLCM;
 LCM_RS = 1;
 LCM_RW = 0;
 LCM_E = 0; //若晶振速度太高可以在这后加小的延时
 LCM_E = 0; //延时
 LCM_E = 1;
}
//写指令
void WriteCommandLCM(unsigned char WCLCM,BuysC) //BuysC为0时忽略忙检测
{
 if (BuysC) ReadStatusLCM(); //根据需要检测忙
 LCM_Data = WCLCM;
 LCM_RS = 0;
 LCM_RW = 0; 
 LCM_E = 0;
 LCM_E = 0;
 LCM_E = 1; 
}
//读数据
unsigned char ReadDataLCM(void)
{
 LCM_RS = 1; 
 LCM_RW = 1;
 LCM_E = 0;
 LCM_E = 0;
 LCM_E = 1;
 return(LCM_Data);
}
//读状态
unsigned char ReadStatusLCM(void)
{
 LCM_Data = 0xFF; 
 LCM_RS = 0;
 LCM_RW = 1;
 LCM_E = 0;
 LCM_E = 0;
 LCM_E = 1;
 while (LCM_Data & Busy); //检测忙信号
 return(LCM_Data);
}
void LCMInit(void) //LCM初始化
{
 LCM_Data = 0;
 WriteCommandLCM(0x38,0); //三次显示模式设置，不检测忙信号
 Delay5Ms(); 
 WriteCommandLCM(0x38,0);
 Delay5Ms(); 
 WriteCommandLCM(0x38,0);
 Delay5Ms(); 
 WriteCommandLCM(0x38,1); //显示模式设置,开始要求每次检测忙信号
 WriteCommandLCM(0x08,1); //关闭显示
 WriteCommandLCM(0x01,1); //显示清屏
 WriteCommandLCM(0x06,1); // 显示光标移动设置
 WriteCommandLCM(0x0C,1); // 显示开及光标设置
}
//按指定位置显示一个字符
void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData)
{
 Y &= 0x1;
 X &= 0xF; //限制X不能大于15，Y不能大于1
 if (Y) X |= 0x40; //当要显示第二行时地址码+0x40;
 X |= 0x80; // 算出指令码
 WriteCommandLCM(X, 0); //这里不检测忙信号，发送地址码
 WriteDataLCM(DData);
}
//按指定位置显示一串字符
void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData)
{
 unsigned char ListLength;
  ListLength = 0;
 Y &= 0x1;
 X &= 0xF; //限制X不能大于15，Y不能大于1
 while (DData[ListLength]>0x20) //若到达字串尾则退出
  {
   if (X <= 0xF) //X坐标应小于0xF
    {
     DisplayOneChar(X, Y, DData[ListLength]); //显示单个字符
     ListLength++;
     X++;
    }
  }
}
//5ms延时
void Delay5Ms(void)
{
 unsigned int TempCyc = 5552;
 while(TempCyc--);
}
//400ms延时
void Delay400Ms(void)
{
 unsigned char TempCycA = 5;
 unsigned int TempCycB;
 while(TempCycA--)
 {
  TempCycB=7269;
  while(TempCycB--);
 };
}